The invention relates to a household laundry dryer, having a filter container and a method for filtering condensate water in a household laundry dryer.
Laundry dryers with a closed process air circuit are generally known, which comprise a heat exchanger coupled to the process air circuit, with the heat exchanger being used to cool down and condense warm and humid process air conducted out of a laundry drum. The heat exchanger may be an air-air heat exchanger or a heat exchanger of a heat pump for instance.
For instance, WO 2008/119611 A1 discloses a method and a washing apparatus for cleaning a component, in particular an evaporator of a heat pump, as well as a washer-dryer or tumble dryer with such an apparatus. In order to clean the component arranged within the process air circuit, condensate water, which is obtained in the process air circuit from the drying of damp laundry and is caught in a condensate water tub, is routed to a washing tub provided above the heat exchanger and released onto the component to be cleaned as a gush of water by abruptly opening onto the exit side. In particular, lint and other impurities can be cleaned off using the washing apparatus. The then heavily lint-laden water re-enters the condensate water container following the washing process. It is nevertheless disadvantageous here for the condensate water used as washing liquid to itself contain lint, which may accumulate on the component to be cleaned during the cleaning and/or washing process and decrease a cleaning effect. In order to remove lint from the condensate water container, this can be removed and emptied from the laundry dryer after a drying process. In the case of some laundry dryers, the condensate water container can be automatically pumped out into a drain.
The generic DE 1 410 851 generally relates to dry cleaning devices and to chemical cleaning methods and in particular to an improved hydraulic flow circuit for a dry cleaning device, with it being possible to implement the chemical cleaning in a programmed sequence, and with the solvent not only be constantly filtered during the cleaning process but instead also be renewed during the subsequent working periods of the program so that the hydraulic flow circuit is prepared for a newly programmed work sequence. The filter facility may comprise several porous tubes, which are arranged in a filter housing and are supported by a separation or division plate, so that the entire solvent flowing through the filter facility flows through the tubes, which consist of a conventional design and may be given a coating made of an auxiliary filter material, for instance made of diatomite so as to narrow the pores and to render more effective the filter for filtering out dirt particles with a size of 1 micron or below. An automatic backwashing of the tubes which takes place under the effect of gravity can be implemented by a large amount of completely filtered solvent, which is found above the separation plate. This thus means that the tubes are cleaner at the end of each backwashing process. Instead of the filter tubes, filters with different designs can also be used with differently formed filter surfaces for the purpose of achieving the same results. A non-generic dry cleaning device with a filter apparatus for the cleaning fluid, which has porous tubes, which are cleaned by means of a backwashing, is also known from GB 1 025 081. Nevertheless, the two cited publications are restricted to dry cleaning which is typically unsuitable for household use and its special requirements. On account of the tubes used, the filters which are needed for the very minimal pore diameter when cleaning the cleaning liquid, are therefore complex, bulky and expensive and are not suited to cleaning condensate water.